Fundamental to any wheeled vehicle, such as all-terrain vehicles (“ATVs”) and recreational off-road vehicles (“ROVs”) are wheels carried by axles. Live axles are driven by the vehicle's engine, and the turning axle causes the wheels to rotate. The coupling between the axle and the wheel ensures that energy provided by the engine can translate into movement of the wheel and ultimately propelling the vehicle. The axle has an axle nut at the end of the axle to hold the wheel and perhaps a hub assembly to the axle. Occasionally, the axle nut can work loose or even fall off the axle. Previous attempts at solving this problem, such as a simple cotter pin passing through the axle nut, are often inadequate. In some cases, the cotter pin shears off under high impact loads. These attempts provide no effective impediment to the axle nut loosening—merely an indication that the axle nut has rotated some unknown degree. There is a need for a lightweight and economical device to ensure that the axle nut does not rotate relative to the axle and loosen.